Prepopulate blog in b.entry_set.all()[i].blog ?

[Carsten Fuchs]

Dear Django group,

with Django 1.11.15, using the example models Blog and Entry at
<https://docs.djangoproject.com/en/2.1/topics/db/queries/#related-objects> for
reference, I have code like this:

b = Blog.objects.get(name="...")
for e in b.entry_set.all():
print(e.blog)

Obviously, e.blog == b, but I found that for each e, the access to e.blog causes
a subquery to fetch the blog object.

While I understand the concepts of select_related() and prefetch_related(), I
was surprised that the e.blog attributes are not prepopulated with b. Why is
that and what is the proper way to fix the problem?

Best regards,
Carsten

[Carsten Fuchs]

Can anyone help please?

[Tim Graham]

It seems to be a bug as reported in https://code.djangoproject.com/ticket/29908. The ForeignKey must use to_field to reproduce the problem.